1. Field of the Invention
The present invention relates to the field of gas turbines. It refers to a method for monitoring the supply system of a gas turbine having a multiburner system, said supply system comprising at least one distribution system, via which a pressurized medium required for operating the multiburner system is distributed to a plurality of individual burners opening into a combustion chamber.
The invention refers, furthermore, to an apparatus for carrying out the method, comprising a plurality of burners which open into a combustion chamber and which are supplied via a fuel distribution system with a pressurized liquid fuel.
2. Discussion of Background
In modern gas turbines which are equipped with low-emission multiburner systems, the fuel is conveyed to the burners or fuel lances via a complex fuel distribution system. The same applies to water which is distributed to the burners via a corresponding water distribution system for the purpose of reducing the NOx emission. A series of switching valves, nonreturn valves and filters, which allow the fuel (water) to be distributed properly to the burners, is installed in the fuel and water lines.
While the plant is being assembled or operated, malfunctions of the fuel or water system may occur. For example, individual nonreturn valves may fail or switching valves may be wrongly activated. Moreover, in many cases, it has been shown, in practice, that impurities in the fuel system lead to the clogging of individual filters or fuel nozzles. In other cases, the regulating valves and fuel nozzles are subject to erosion phenomena due to small solid particles entrained in the fuel.
All the abovementioned irregularities in fuel distribution (or water distribution) lead to an uneven load on the burners and, consequently, to increased thermal load on individual hot gas parts. They thus shorten the lifetime of the gas turbine. It is therefore desirable to have the possibility of detecting malfunctions in the supply systems, in particular in fuel or water distribution, reliably at an early stage and thereby enable the operator of the gas turbine to conduct a clear analysis of the state of his plant.